From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Visit to the Rover factory to investigate their Girling Brake system.
| Identifier | ExFiles\Box 120\3\ scan0061 | |
| Date | 9th November 1933 | |
| W/S. To Sg.{Arthur F. Sidgreaves - MD} from Da.{Bernard Day - Chassis Design} c. Wor.{Arthur Wormald - General Works Manager} E.{Mr Elliott - Chief Engineer} Hs.{Lord Ernest Hives - Chair} He/Hm.{Capt. W. Hallam - Head Repairs} BY.{R.W. Bailey - Chief Engineer} HDY.{William Hardy} Da.{Bernard Day - Chassis Design}2/HP.9.11.33. Visit to Rovers. Rm.{William Robotham - Chief Engineer} and I visited the Rover Co's factory yesterday. We saw Mr Wilks, Managing Director, and Mr M.Wilks, Chief Designer. The object of the visit was to find out what we could about the Girling Brake. This brake has been adopted by the Rover Co. on their 10 and 12 HP. models and is being applied to the "pilot"model. It supersedes the Lockheed hydraulic brake. The advantages they expect to gain are reduction of "sponge" which is present in the Lockheed system because of the rubber tubes, absence of squeaks, and elimination of the disastrous consequences of leaving the hand brake on accidentally. They say Lockheeds are continually producing new fluids in an effort to raise the boiling point. We raised the question of increased wear of one shoe due to the floating fulcrum. They say they must have this feature because of the additional braking it gives them, and it is of course already present on the Lockheed brakes they are discarding. The additional wear of one shoe is approximately 60%. They carried out tests to find out the effect of fixing the fulcrum and discovered, as we anticipated, a large amount of additional friction in the operating mechanism as load increased. They use .012 clearance between shoe and drum, a ratio of 44 to 1 between pedal and shoe tip, aluminium shoes with rivets right through the lining and steel drums. This is a combination we have found experimentally to be impossible owing to the transmission of heat from drum to shoe. Certainly the car we tried seemed to have very good brakes. They gave the distribution rationas 70% to the front. We raised the question of the mechanism in the shoes rusting up in time. They agreed that it was important but expected to be able to protect the working surfaces by chromium | ||